Full disclosure: I received a TOFU board free of charge from Oratek for this, and writing this blog post about the work was part of the deal. It all started with a peculiar bug report I received for my Plebian project; the CM4IO board image wasn't working quite right on the Oratek TOFU CM4 carrier board. USB and PCIe weren't working at all. Usually, this wouldn't be very surprising; device trees are board specific after all. However, as I looked into the TOFU board schematic, I noticed that i...
